   "The Golden Ratio - (1+sqrt5)/2."
   (/ (inc (Math/sqrt 5)) 2))
 
-(defn digits [n]
+(defn digits
   "**digits :: Int -> [Int]**
   Converts a number n into a list of its digits."
-  (map #(Character/digit % 10) (str n)))
-
-(defn narcissistic? [n exp]
+  [n] (map #(Character/digit % 10) (str n)))
+
+(defn narcissistic?
   "A number written as the sum of its nth powers.
   Exp.: 1634 = 1^4 + 6^4 + 3^4 + 4^4."
+  [n exp]
   (->> (digits n)
        (map #(Math/pow % exp))
        (reduce +)

                  (inc (memo-collatz c (next-collatz n))))
           n)))

(defn parse-grid [grid-str dimension]
  "**parse-grid :: String -> [[Int]]**
  Converts a string into a dimension x dimension vector of integers."
  (vec (map vec (partition dimension (map #(Integer. %) (.split grid-str "\\s+"))))))

(defn product


(def tens ["twenty" "thirty" "forty" "fifty" "sixty" "seventy" "eighty" "ninety"])

(defn to-words
  "Converts a number (up to 1000) into its string representation, omitting spaces.
  Example: (to-words 115) => 'onehundredandfifteen'."
  [n]
  (cond
    (< n 20) (nth singles (dec n))
    (< n 100) (if (factor? n 10)
